The present invention is related to power conversion, and in particular to AC-AC power converters for driving electric motors.
In many applications (e.g., aircraft applications) AC-AC converters are employed to drive an electric alternating current (AC) motor that is used as the prime mover for a specified mechanical load. In these applications, the AC motor and motor controller can be integrated into a single unit to form an integrated system. To meet AC input power quality and electromagnetic interference (EMI) requirement, an autotransformer rectifier unit (ATRU) and power quality EMI filter are provided at a front end that filters an AC input and converts the AC input to a DC output. A DC-AC converter (inverter) converts the DC output to an AC output for supply to the AC motor.
In aircraft applications, as well as others, the weight of a system has a direct influence on the overall cost of the system. The weight of the autotransformer is a function of the relative power rating of the transformer. A higher relative power rating results in a weight penalty.